LM2743 Datasheet | National Semiconductor

LM2743 N-Channel FET Synchronous Buck Regulator Controller for Conversion from 3.3V April 2004 LM2743 N-Channel FET Synchronous Buck Regulator Controller for Conversion from 3.3V General Description The LM2743 is a high-speed, N-Channel synchronous buck regulator controller with a 2%, 0.6V feedback reference voltage intended to make down conversion from 3.3V to as low as 0.6V easy. A fixed-frequency voltage-mode PWM control architecture is used, that is adjustable from 50k Hz to 2MHz through an external resistor. This wide range of PWM frequencies gives the power supply designer the flexibility to make tradeoffs among ponent size, cost, noise and efficiency. The power MOSFETs can run on a separate 1V to 16V (Input Voltage, VIN) (Note 2) rail while the regulator is biased from a 3V to 6V (IC Input Voltage, VCC), 2m A rail. A power-good flag, precision shutdown threshold and soft start Features make power supply tracking and sequencing easy. The LM2743 employs output under-voltage and over-voltage flag, and current limit. Current limit is achieved by monitoring the voltage drop across the on resistance of the low-side MOSFET. The adaptive non-overlapping MOSFET gate drivers help avoid potential shoot-through problems while maintaining high efficiency. Both high-side and low-side MOSFETs are the lower cost N-Channel type, and the IC can accept a bootstrap structure to saturate the high-side MOSFET for highest efficiency. Features MOSFET input voltage (VIN) from 1V to 16V (Note 2) IC input voltage (VCC) from 3V to 6V Output voltage adjustable down to 0.6V Power good flag and output enable Output over-voltage and under-voltage flag FB voltage: 2% over temperature Current limit without series sense resistor Adjustable soft start Tracking and sequencing with shutdown and soft start pins n Switching frequency from 50 k Hz to 2 MHz n TSSOP-14 package n n n n n n n n n Applications n n n n 3.3V Buck Regulation Set-Top Boxes/ Home Gateways Core Logic Regulators...